Weft thread laying apparatus with combing element

ABSTRACT

A weft thread magazine for a warp knitting machine has two endless transfer chains. The chains have holders for retaining weft threads in parallel and presenting them to a needle bed. Also included is a thread laying arrangement which transports the weft threads from one transfer chain to the other, and which is provided with a comb arrangement. The comb arrangement includes a comb element having at least one combing peg which is introduced between the weft threads proximate to one of the transfer chains and which moves parallel to the weft threads and is removed proximate to the other transfer chain. A carriage has a thread guide for guiding at least one weft thread into a position parallel to a previously laid weft thread. The comb element is carried on the end of the carriage directed toward the needle bed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to weft thread inserting apparatus and, inparticular, to a transversely movable, weft thread apparatus thatcarries both a thread guide and a combing element, thereby facilitatingand simplifying the laying and combing of weft threads.

2. Discussion of the Relevant Art

In a known arrangement of this type (DE-PS No. 2063696) the threadlaying arrangement comprises a continuous band running diagonally to thetransport arrangement and having a combing element whose pegs intrudeinto the space between the weft threads. The speed of this band isgeared to the speed of transport of the weft threads so that themovement of the pegs is effectively parallel relative to the directionof the weft threads. By means of these pegs, it is possible to separateweft threads which have become tangled because of mislaying between thetransport chains or because of swinging which has occurred. Suchtangling is a particular problem when dealing with "hairy" type of weftthreads.

This combing arrangement is structurally quite complex, requiring arather complicated drive arrangement with many gear wheels and chains.Furthermore, a substantial mass must be moved. Also, the guiding of thepegs is not very precise since the band is rather long, sags in themiddle and tends to vibrate at certain machine speeds. As a consequence,the distance between neighboring weft threads cannot be less than acertain amount. Correspondingly, the wastage is particularly large atthe turning points of the continuously fed weft thread at the transportchains.

Weft thread magazines without combing arrangements which include threadlaying arrangements are well-known (DE-PS No. 2013694). Such threadlaying arrangements include a carrier with at least one thread guide.This arrangement guides the appropriate weft threads parallel to thealready laid weft threads between a holding means in one transfer chainto the other transfer chain. For this purpose a carriage, transverselymovable between the transfer chains is provided into which a carrier maybe mounted for reciprocation in the transfer (forward) direction. Thecarrier is steered by a guiding band which is connected to a steeringarrangement. Both ends of the guiding band are longitudinally movable inthe transfer direction, which enables the thread guides to continuouslylay continuous weft threads between opposite holding means on a firstand then a second chain, periodically displacing the threads by anappropriate number of holding elements on the outside of this secondtransfer chain and then completing the cycle by moving back in theopposite direction. By this means the weft threads may be continuouslyor endlessly laid. There are, however, thread guide arrangements whichlay the thread merely from one transfer chain to the other whereuponthey are cut. There are also thread laying arrangements in which theparallel movement of the thread guides with respect to the already laidthreads is achieved in a different manner. For example, by altering thespeed of the transfer chains in the vicinity of the thread layingarrangement.

SUMMARY OF THE INVENTION

Therefore it is one object of the present invention to provide a weftthread magazine having a relatively simple combing arrangement but whichnevertheless provides a more accurate guiding of the combing pegs.

It is another object of the present invention to provide a combingelement that moves parallel with respect to moving weft threads and iswithdrawn before reaching the transfer chains holding such threads. Itis yet another object of the present invention to provide a threadmagazine capable of operating at high speed with closely spaced weftthreads to reduce wastage and yet avoid tangling.

It is still another object of the present invention to mount a combelement on a transversely moving thread guide carrier to facilitateaccurate combing since the carrier runs at the same level as the weftthread.

It is a further object of the present invention to mount areciprocatable comb on the carrier that support the guides for the weftthread to reduce the moving mass and avoid the need for an independentpower source for moving the comb.

A weft thread magazine for a warp knitting machine having a needle bed,according to the principles of the present invention, comprises, incombination, a pair of endless transfer chain means, each having aholding means. These holding means retain weft threads in parallel andpresent them to the needle bed. Also included is a thread layingarrangement for transporting weft thread from one of the pair oftransfer means to the other. The thread laying arrangement includes acarriage means having at least one thread guide. The thread guide canguide at least one of the appropriate weft threads into a positionparallel to an already laid weft threads. The magazine also includes acombing element mounted on the carriage means. The element has at leastone combing peg and is operable to introduce the peg between weftthreads proximate one of the pair of transfer chain means. The combingelement is also operable to move its peg parallel to the weft threadsand to remove the peg proximate the other transfer chain means.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more fully understood, it will now bedescribed, by way of example, with reference of the accompanyingdrawings in which:

FIG. 1 is a schematic side view, partially in cross section, of a warpknitting machine equipped with the weft thread laying apparatus andcombing apparatus, according to the principles of the present invention;

FIG. 2 is a plan view of the needle bed of the machine shown in FIG. 1from a weft thread pick-up area to the delivery area proximate theneedle bed showing the thread laying and combing devices;

FIG. 3 is a sectional view of the wedge and adjacent elements of FIG. 1;

FIG. 4 is a sectional side view of a combing element which is analternate to that shown in FIG. 1; and

FIG. 5 is a sectional view of the combing element of FIG. 4 showing itsoperation.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the figures, and in particular to FIG. 1, thisdiscloses a warp knitting machine 10 and weft thread magazine 11 of theinstant invention. The warp knitting machine 10 includes a needle bed 12which has a needle bar 14 having a plurality of hook needles 16disposed, thereon in a conventional manner. The needles 16 cooperatewith a slider mechanism 18 and a knockover sinker 20 all of which are aconventional design. On both ends of the needle bed 12 there is provideda pair of endless transfer chain means 22 and 24 which move in alongitudinal direction as shown by arrows 26 and 26'. The transferchains are provided with a plurality of holding means 28 equally spacedand fixed to the transfer chains 22 and 24 in a conventional manner. Theholding means are holders preferably having a pawn-like shape (a spheredisposed upon a truncated cone) and serve to hold the weft thread onceit is wrapped therearound.

The transfer chains are endless and are led over a plurality of rollers30, 32, 34, 36 and 38 of which at least one is connected to a source ofdriving power, not shown. In the transverse direction (perpendicular tothe transfer chains) a pair of support rails 40 and 42 are disposed oneabove the other. A carriage means including carriage 44 is drivenforward and backward in a conventional manner, by means of a chain 46,belt or the like, as shown by arrow 48 in FIG. 2.

A thread laying arrangement employs the carriage means 44 which includesa frame 50 (FIGS. 1 and 2) and a pair of rollers or wheels 52 and 54journaled in the upper portion of frame 50, in a conventional manner anda pair of rollers or wheels 56 and 58 as journaled on the lower portionof the frame in the same manner. The rollers 52 and 54 are adapted toride on the support rail 42 and the rollers 56 and 58 are adapted toride on the support rail 40, permitting the carriage 44 to move in atransverse direction freely thereon. The carriage 44 is also providedwith an upper thread guide 60 which is provided with a plurality ofapertures 61 therein through which the weft threads 62 a,b,c and d arethreaded. Preferably, the lower portion of the carriage frame 50 isprovided with an axial bearing shown herein as a bushing 64 having anaperture therein which is adapted to slidably receive guide rod 68 ofcarrier 67 herein (FIGS. 1 and 2). One end of guide rod 68 is providedwith a plurality of thread guides 70 disposed thereon, in a conventionalmanner and the other end of rod 68 is provided with a pair of rollers 72and 74 journaled thereon. The rollers 72 and 74 are located on bothsides of a flexible guide band 76 preferably made of steel. The guiderod 68 is permitted to freely move within the aperture of bushing 64 andits movement thereof is obviously controlled by the position of rollers72 and 74.

One end of the flexible guide band 76 is preferably rigidly connected toa steering means 78 which is provided with a housing 80 having anopening 82 therein adapted to receive rollers 72 and 74 therein, as wellas retain band 76 by means of a nut 84 provided therefore. The steeringapparatus 78 has its housing 80 coupled by means of a rod 86 and a lever88 articulated therewith. The lever 88 is provided with a contact roller90 journalled thereon which continually cooperates with a driven cam 92having a curved surface 94 which cooperates with roller 90 therebymoving lever 88 and rod 86 in the direction of arrow 96 which is in thelongitudinal direction. A spring 98 maintains tension on lever 88 sothat contact roller 90 faithfully follows the surface 94 of cam 92.

On the opposite end of the needle bed proximate transfer chain 22 asecond steering apparatus 78' is provided. Steering apparatus 78'includes a housing 80' which is provided with an aperture 82' and isdriven in the direction of arrow 96' by rod 86', lever 88' and a contactroller and cam arrangement, not shown, similar to the drivingarrangement shown with regard to the steering apparatus 78. The band 76is retained in the housing 80' by means of nut 84' and is also providedwith a spring device 100 disposed between the nut and rear surface ofthe housing so that by tightening or loosening the nut 84; the tensionof the flexible guide band 76 may be adjusted.

As shown in FIGS. 1 and 2 the weft threads 62 a,b,c and d are taken fromspools 62 a',b',c' and d' (see FIG. 2) and threaded through upper threadguide 60 and then through thread guides 70 and by means of the movementof the carriage 44 and guide 70 the weft threads 62 are wrapped aroundthe holding devices 28 on the transfer chains. The weft threads 62 aremoved rearwardly in the direction of arrow 96 when they find themselvesoutside of the transfer chains 22 and 24 and this rearward longitudinalmovement is repeated each time the carriage is moved in the area oftransfer chain 22 and then in the area of transfer chain 24, asexplained hereinafter.

Preferably, holding devices 28 are spaced so that the distance S (FIG.2) between adjacent holding elements 28 is no closer than 8 millimeters.Consequently, the length of thread elements 65 which are located on theoutside of holders 28 (and are illustrated merely schematically) andwhich are later cut away, are kept extraordinarily short, thus, ofcourse, resulting in saving of thread material.

In the embodiment of FIGS. 1 through 3, a combing element 122 is locatedat that end of carrier 67 directed towards needle bed 12. Combingelement 122 is attached to carrier 67 by hinge means 124 whose axis runsperpendicular to transfer chains 22 and 24, allowing free end 130 tolift. Element 122 comprises a cylindrical holder 126 provided with aplurality of downwardly directed pegs 128 which are sized and shaped toseparate neighboring weft threads 63. Four pegs 128 are shown, it beingpreferable that the number be at least as great as the number of threadguides 70. As indicated in phantom in FIG. 1 the free end of holder 126can be swung upwardly so that pegs 28 are removable from the spacesbetween the threads.

For this purpose, wedge member 140 and 140', shaped as solid triangularprisms, are provided on both sides of the machine: on the inside of andproximate to said chain 24 and 22, respectively. Each wedge has aninclined surface over which the free end 130 of holder 126 can ride. Theinclined surface of wedge 140 is shown in FIG. 3 as surface 142, itbeing understood that the side view of wedge 140' is similar and is themirror image thereof. In a manner not illustrated in the drawings, wedge140 is connected with housing 80 and wedge 140' with housing 80'.Consequently, wedges 140 and 140' move in unison with housings 80 and80' so that the contact of the holder 126 on the incline is maintainedeven when the carrier is displaced backwards in the manner describedhereinafter.

Inasmuch as combing element 122 is advantageously attached to a free endof the thread guide carrier 67 that protrudes from axial bearing 64,combing element 122 requires extremely little additional power. Also,since rod 68 of carrier 67 carries thread guide 70 on one side of itsaxial bearing 64, and on the other side, combing element 122 as well asrollers 72, 74, forces act substantially equally on both sides ofbearings 64 and the load on rod 68 can be advantageously balanced. Also,as a result of the foregoing construction, weft threads can be spaced 8millimeters or less. This close spacing is possible because combingelement 122 is precisely positioned with respect to the weft threads toprevent tangling before they reach needle bed 12. As a consequence ofthis minimal separation, there is very small wastage at the turnaroundpoints.

In operation, transfer chains 22 and 24 are driven in a forward orlongitudinal direction as shown by arrows 26 and 26'. Carriage 44 ismoved in the direction of arrow 48 by means of a reciprocating drivearrangement 46 whereby it is made to come to rest for a short period oftime at the end of travel of the carriage which occurs when rollers 72and 74 are positioned in the housing 80' where the rearward movement istimed to take place. The carriage is then moved in a longitudinaldirection as shown by arrow 96 when the steel band 76 is moved backwardsand forwards by the steering apparatus which is coupled to cam 92, viarod 86 and via rod 88, as explained earlier. The rearward movement isadjusted to move the thread guides 70 a distance of four holding devices28 as determined by the cam surface 94 on cam 92. As the carriage 44starts to move towards the left, as shown in FIG. 2, a small forwardmovement of thread guide 70 occurs because of the segment 102 of cam 92.This movement comes to a complete halt as the cam portion 104 comes intocontact with contact roller 90. This occurs when the carrier 44 islocated inside of the transfer chains 22 and 24. When the carriage findsitself outside of the transfer chains 22 and 24 cam segment or portion106 causes the linkage 86 and 88 to move the thread guide 70 sharply ina rearward direction thereby permitting the thread to move past theholding devices 28 on transfer chains 22 or 24 and the wrap around iscompleted as the carriage then returns towards the opposite transferchain.

As carriage 44 transversely reciprocates as indicated by arrow 48, itlays weft threads 63 across opposite holders 28 on chains 22,24. For thecondition shown in FIG. 2, carrier 67 and holder 126 are moving parallelto weft threads 63, pegs 156 having been inserted between threads 63 tocomb and separate them. Since rollers 72 and 74 move rod 68 forward atthe same speed as weft threads 63, comb element 122 moves parallel butnot against weft threads 63. As comb element 122 moves towards the right(FIG. 2), eventually free end 130 of holder 126 reaches wedge 140' andrides upwardly across inclined surface 142 (FIG. 3) thereby lifting pegs128 from between weft threads 63. At this time, rollers 72 and 74 entercavity 82' of housing 80'. Thereafter, housing 80' is moved backwardlyas described above. However, since wedge 140' is supported by housing80', holder 126 and wedge 140' move together so that free end 130 doesnot fall from inclined surface 142. After housing 80' completes thisretrograde motion, wrapping weft threads 63 around holding devices 28,carriage 44 progresses in the opposite direction, that is, to the leftin FIG. 2. As a result, free end 130 of holder 126 descends the inclinedsurface 142 of wedge 140'. Accordingly, pegs 128 are reinserted betweenweft threads 63 after clearing chain 22. The combing element 122proceeds toward housing 80 which eventually causes wedge 140 to liftholder 126 in a manner similar to that previously described for wedge140'.

It will be appreciated that since combing element 122 combs andseparates weft threads 63 just prior to their entry into needle bed 12,the spacing between weft threads can be kept small and tangling isunlikely even at relatively high machine speeds. Also, since carrier 67carries both thread guides 70 and combing element 122 the complexity ofconstruction is reduced considerably. The mass which has to be moved isalso correspondingly less. Furthermore, there is no requirement for aseparate drive means for combing arrangement 122. Also, because thecombing arrangement possesses the same precision of guidance as threadguide 70, undesireable changes in the height orientation of pegs 128 areunlikely since carrier 67 runs at the exact height without swinging.

A further embodiment is illustrated in FIGS. 4 and 5. In thisembodiment, an alternate comb element 150 is provided at the end of rod68 of carrier 67. The element comprises an axle 152 bracketed onto adownward tab of rod 68. Axle 152 is inserted into rotatable housing 154which is a sleeve sized to fit axle 152 without binding. On theunderside of housing 154 are provided pegs 156 which serve to separateweft threads 63. Housing 154 is arranged so that upon its rotation aboutan axis parallel to transfer chains 22, 24, pegs 156 lift from the levelof weft threads 63. On the other side of housing 154 there is provided astriker arm 160 in the form of a cylindrical rod. Since the combinedweight of pegs 156 will exceed that of striker arm 160, a normalorientation due to gravity will be as illustrated in FIG. 4. If desired,however, this normal orientation can be urged by the provision of asuitable biasing spring element (which is not illustrated). On bothsides of the machine (in the same positions as wedges 140 and 140')there are located striker plates as follows: a striker plate 170 locatedat chain 22 (FIG. 5) it being appreciated that positioned at chain 24 isanother striker plate (not illustrated) similar to plate 170 andconfigured as the mirror image thereof.

Striker arm 160, extending in the opposite direction from pegs 156, issized to contact striker plate 170 proximate to transfer chain 22. Thisand the complimentary striker plate are so positioned that pegs 156disengage the weft threads before reaching the chains 22, 24irrespective of the direction of movement. Such disengagement at the endof transverse motion is shown in phantom in FIG. 5 wherein striker bar160 contacts striker plate 170, causing housing 154 to rotate and removepegs 156 from contact with weft threads 63

For the embodiment of FIGS. 4 and 5, the operation of comb element 150is similar to that previously described except that instead of lifting,pegs 156 rotate upwardly out of engagement with weft threads 63 when thestriker arm 160 engages striker plate 170, as illustrated in phantom inFIG. 5. Again, striker plate 170, may if desired be coupled to housing80' to move in unison with comb element 150 so that striker arm 160 doesnot disengage striker plate 170 when housing 80' retrogresses carriage44, at the extreme end of its travel.

It will be appreciated that various modifications to the foregoingembodiments are possible in light of the above teachings. For example,in another embodiment the combing pegs may be attached to a holder whichis mounted about an axis perpendicular to the forwarding direction and,in the vicinity of the forwarding chains 22, 24, this holder is causedto run up the incline of a wedge by which means the pegs are similarlyremoved from the level of the weft threads. Also, in order to ensuregreater security against rotation of carrier 67 about its axis, it canbe suitably locked or keyed into radial bearing 64. Alternatively,carrier 67 can be constructed from a pair of rods connected to eachother and each set into radial bearing 64. On the other hand, two radialbearings can be utilized to achieve the same function.

Hereinbefore has been disclosed an efficient device for installing andcombing weft threads in warp knitting capable of operating at relativelyhigh speeds without tangling. It will be understood that various changesin the details, materials, arrangement of parts and operating conditionswhich have been herein described and illustrated in order to explain thenature of the invention may be made by those skilled in the art withinthe principles and scope of the instant invention.

Having set forth the nature of the invention, what is claimed is:
 1. Aweft thread magazine for a warp knitting machine having a needle bed,said magazine comprising, in combination:(a) a pair of endless transferchain means each having holding means for retaining weft threads inparallel and for presenting them to said needle bed; (b) a thread layingarrangement for transporting weft threads from one of said pair oftransfer means to the other, said arrangement including a carriage meanshaving at least one thread guide for guiding at least one of theappropriate weft threads into a position parallel to an already laidweft thread; and (c) a combing element mounted on said carriage meansand having at least one combing peg and being operable to introduce saidpeg between weft threads proximate one of said pair of transfer chainmeans, to move said peg parallel to the weft threads and to remove saidpeg proximate the other transfer chain means.
 2. A weft thread magazineaccording to claim 1 wherein said combing element is mounted on aportion of said carriage means directed toward said needle bed.
 3. Aweft thread magazine according to claim 2 wherein said carriage meanshas a plurality of thread guides and wherein said combing element has aplurality of combing pegs equaling in number said plurality of threadguides.
 4. A weft thread magazine according to claim 2 wherein saidcarriage means is transversely movable between said pair of chain means,said carriage means comprising:(a) a carrier having a free end and beingslidably mounted in said carriage means, said combing element beingattached to said free end of said carrier; (b) a guide band transverselydisposed across said pair of chain means; (c) a steering means attachedto opposite ends of said band for positioning it.
 5. A weft threadmagazine according to claim 4 wherein said carriage means includes abearing into which said carrier is journaled.
 6. A weft thread magazineaccording to claim 5 wherein said carrier comprises:(a) a rod journaledin said bearing; and (b) a pair of rollers mounted on said rod forengaging said guide band, said rod supporting said thread guide on oneside of said bearing and on its other side said rollers and said combingelement.
 7. A weft magazine according to claim 1,2,4 or 6 wherein saidcombing element includes an outwardly projecting striker arm, saidcombing peg and arm being mounted for rotation about an axis parallel tosaid chain means, said magazine including a pair of striker plates eachdisposed proximate a different respective one of said pair of chainmeans for engaging said arm and rotating said peg.
 8. A weft magazineaccording to claims 1,2,4 or 6 wherein said combing element includes apeg holder hingeably mounted to rotate about an axis perpendicular tosaid chain means, said magazine including a pair of wedge members eachdisposed proximate a different respective one of said pair of chainmeans for engaging and rotating said holder.
 9. A weft magazineaccording to claim 1 wherein said thread laying arrangement is operableto lay threads in an endless manner, said holding means comprising aplurality of holders spaced less than eight millimeters apart.